Contract Source Code:
File 1 of 1 : XDEFIVault
// File: @openzeppelin/contracts/utils/Counters.sol
// OpenZeppelin Contracts v4.4.1 (utils/Counters.sol)
pragma solidity ^0.8.0;
/**
* @title Counters
* @author Matt Condon (@shrugs)
* @dev Provides counters that can only be incremented, decremented or reset. This can be used e.g. to track the number
* of elements in a mapping, issuing ERC721 ids, or counting request ids.
*
* Include with `using Counters for Counters.Counter;`
*/
library Counters {
struct Counter {
// This variable should never be directly accessed by users of the library: interactions must be restricted to
// the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add
// this feature: see https://github.com/ethereum/solidity/issues/4637
uint256 _value; // default: 0
}
function current(Counter storage counter) internal view returns (uint256) {
return counter._value;
}
function increment(Counter storage counter) internal {
unchecked {
counter._value += 1;
}
}
function decrement(Counter storage counter) internal {
uint256 value = counter._value;
require(value > 0, "Counter: decrement overflow");
unchecked {
counter._value = value - 1;
}
}
function reset(Counter storage counter) internal {
counter._value = 0;
}
}
// File: @openzeppelin/contracts/utils/math/Math.sol
// OpenZeppelin Contracts (last updated v4.8.0) (utils/math/Math.sol)
pragma solidity ^0.8.0;
/**
* @dev Standard math utilities missing in the Solidity language.
*/
library Math {
enum Rounding {
Down, // Toward negative infinity
Up, // Toward infinity
Zero // Toward zero
}
/**
* @dev Returns the largest of two numbers.
*/
function max(uint256 a, uint256 b) internal pure returns (uint256) {
return a > b ? a : b;
}
/**
* @dev Returns the smallest of two numbers.
*/
function min(uint256 a, uint256 b) internal pure returns (uint256) {
return a < b ? a : b;
}
/**
* @dev Returns the average of two numbers. The result is rounded towards
* zero.
*/
function average(uint256 a, uint256 b) internal pure returns (uint256) {
// (a + b) / 2 can overflow.
return (a & b) + (a ^ b) / 2;
}
/**
* @dev Returns the ceiling of the division of two numbers.
*
* This differs from standard division with `/` in that it rounds up instead
* of rounding down.
*/
function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) {
// (a + b - 1) / b can overflow on addition, so we distribute.
return a == 0 ? 0 : (a - 1) / b + 1;
}
/**
* @notice Calculates floor(x * y / denominator) with full precision. Throws if result overflows a uint256 or denominator == 0
* @dev Original credit to Remco Bloemen under MIT license (https://xn--2-umb.com/21/muldiv)
* with further edits by Uniswap Labs also under MIT license.
*/
function mulDiv(
uint256 x,
uint256 y,
uint256 denominator
) internal pure returns (uint256 result) {
unchecked {
// 512-bit multiply [prod1 prod0] = x * y. Compute the product mod 2^256 and mod 2^256 - 1, then use
// use the Chinese Remainder Theorem to reconstruct the 512 bit result. The result is stored in two 256
// variables such that product = prod1 * 2^256 + prod0.
uint256 prod0; // Least significant 256 bits of the product
uint256 prod1; // Most significant 256 bits of the product
assembly {
let mm := mulmod(x, y, not(0))
prod0 := mul(x, y)
prod1 := sub(sub(mm, prod0), lt(mm, prod0))
}
// Handle non-overflow cases, 256 by 256 division.
if (prod1 == 0) {
return prod0 / denominator;
}
// Make sure the result is less than 2^256. Also prevents denominator == 0.
require(denominator > prod1);
///////////////////////////////////////////////
// 512 by 256 division.
///////////////////////////////////////////////
// Make division exact by subtracting the remainder from [prod1 prod0].
uint256 remainder;
assembly {
// Compute remainder using mulmod.
remainder := mulmod(x, y, denominator)
// Subtract 256 bit number from 512 bit number.
prod1 := sub(prod1, gt(remainder, prod0))
prod0 := sub(prod0, remainder)
}
// Factor powers of two out of denominator and compute largest power of two divisor of denominator. Always >= 1.
// See https://cs.stackexchange.com/q/138556/92363.
// Does not overflow because the denominator cannot be zero at this stage in the function.
uint256 twos = denominator & (~denominator + 1);
assembly {
// Divide denominator by twos.
denominator := div(denominator, twos)
// Divide [prod1 prod0] by twos.
prod0 := div(prod0, twos)
// Flip twos such that it is 2^256 / twos. If twos is zero, then it becomes one.
twos := add(div(sub(0, twos), twos), 1)
}
// Shift in bits from prod1 into prod0.
prod0 |= prod1 * twos;
// Invert denominator mod 2^256. Now that denominator is an odd number, it has an inverse modulo 2^256 such
// that denominator * inv = 1 mod 2^256. Compute the inverse by starting with a seed that is correct for
// four bits. That is, denominator * inv = 1 mod 2^4.
uint256 inverse = (3 * denominator) ^ 2;
// Use the Newton-Raphson iteration to improve the precision. Thanks to Hensel's lifting lemma, this also works
// in modular arithmetic, doubling the correct bits in each step.
inverse *= 2 - denominator * inverse; // inverse mod 2^8
inverse *= 2 - denominator * inverse; // inverse mod 2^16
inverse *= 2 - denominator * inverse; // inverse mod 2^32
inverse *= 2 - denominator * inverse; // inverse mod 2^64
inverse *= 2 - denominator * inverse; // inverse mod 2^128
inverse *= 2 - denominator * inverse; // inverse mod 2^256
// Because the division is now exact we can divide by multiplying with the modular inverse of denominator.
// This will give us the correct result modulo 2^256. Since the preconditions guarantee that the outcome is
// less than 2^256, this is the final result. We don't need to compute the high bits of the result and prod1
// is no longer required.
result = prod0 * inverse;
return result;
}
}
/**
* @notice Calculates x * y / denominator with full precision, following the selected rounding direction.
*/
function mulDiv(
uint256 x,
uint256 y,
uint256 denominator,
Rounding rounding
) internal pure returns (uint256) {
uint256 result = mulDiv(x, y, denominator);
if (rounding == Rounding.Up && mulmod(x, y, denominator) > 0) {
result += 1;
}
return result;
}
/**
* @dev Returns the square root of a number. If the number is not a perfect square, the value is rounded down.
*
* Inspired by Henry S. Warren, Jr.'s "Hacker's Delight" (Chapter 11).
*/
function sqrt(uint256 a) internal pure returns (uint256) {
if (a == 0) {
return 0;
}
// For our first guess, we get the biggest power of 2 which is smaller than the square root of the target.
//
// We know that the "msb" (most significant bit) of our target number `a` is a power of 2 such that we have
// `msb(a) <= a < 2*msb(a)`. This value can be written `msb(a)=2**k` with `k=log2(a)`.
//
// This can be rewritten `2**log2(a) <= a < 2**(log2(a) + 1)`
// → `sqrt(2**k) <= sqrt(a) < sqrt(2**(k+1))`
// → `2**(k/2) <= sqrt(a) < 2**((k+1)/2) <= 2**(k/2 + 1)`
//
// Consequently, `2**(log2(a) / 2)` is a good first approximation of `sqrt(a)` with at least 1 correct bit.
uint256 result = 1 << (log2(a) >> 1);
// At this point `result` is an estimation with one bit of precision. We know the true value is a uint128,
// since it is the square root of a uint256. Newton's method converges quadratically (precision doubles at
// every iteration). We thus need at most 7 iteration to turn our partial result with one bit of precision
// into the expected uint128 result.
unchecked {
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
return min(result, a / result);
}
}
/**
* @notice Calculates sqrt(a), following the selected rounding direction.
*/
function sqrt(uint256 a, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = sqrt(a);
return result + (rounding == Rounding.Up && result * result < a ? 1 : 0);
}
}
/**
* @dev Return the log in base 2, rounded down, of a positive value.
* Returns 0 if given 0.
*/
function log2(uint256 value) internal pure returns (uint256) {
uint256 result = 0;
unchecked {
if (value >> 128 > 0) {
value >>= 128;
result += 128;
}
if (value >> 64 > 0) {
value >>= 64;
result += 64;
}
if (value >> 32 > 0) {
value >>= 32;
result += 32;
}
if (value >> 16 > 0) {
value >>= 16;
result += 16;
}
if (value >> 8 > 0) {
value >>= 8;
result += 8;
}
if (value >> 4 > 0) {
value >>= 4;
result += 4;
}
if (value >> 2 > 0) {
value >>= 2;
result += 2;
}
if (value >> 1 > 0) {
result += 1;
}
}
return result;
}
/**
* @dev Return the log in base 2, following the selected rounding direction, of a positive value.
* Returns 0 if given 0.
*/
function log2(uint256 value, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = log2(value);
return result + (rounding == Rounding.Up && 1 << result < value ? 1 : 0);
}
}
/**
* @dev Return the log in base 10, rounded down, of a positive value.
* Returns 0 if given 0.
*/
function log10(uint256 value) internal pure returns (uint256) {
uint256 result = 0;
unchecked {
if (value >= 10**64) {
value /= 10**64;
result += 64;
}
if (value >= 10**32) {
value /= 10**32;
result += 32;
}
if (value >= 10**16) {
value /= 10**16;
result += 16;
}
if (value >= 10**8) {
value /= 10**8;
result += 8;
}
if (value >= 10**4) {
value /= 10**4;
result += 4;
}
if (value >= 10**2) {
value /= 10**2;
result += 2;
}
if (value >= 10**1) {
result += 1;
}
}
return result;
}
/**
* @dev Return the log in base 10, following the selected rounding direction, of a positive value.
* Returns 0 if given 0.
*/
function log10(uint256 value, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = log10(value);
return result + (rounding == Rounding.Up && 10**result < value ? 1 : 0);
}
}
/**
* @dev Return the log in base 256, rounded down, of a positive value.
* Returns 0 if given 0.
*
* Adding one to the result gives the number of pairs of hex symbols needed to represent `value` as a hex string.
*/
function log256(uint256 value) internal pure returns (uint256) {
uint256 result = 0;
unchecked {
if (value >> 128 > 0) {
value >>= 128;
result += 16;
}
if (value >> 64 > 0) {
value >>= 64;
result += 8;
}
if (value >> 32 > 0) {
value >>= 32;
result += 4;
}
if (value >> 16 > 0) {
value >>= 16;
result += 2;
}
if (value >> 8 > 0) {
result += 1;
}
}
return result;
}
/**
* @dev Return the log in base 10, following the selected rounding direction, of a positive value.
* Returns 0 if given 0.
*/
function log256(uint256 value, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = log256(value);
return result + (rounding == Rounding.Up && 1 << (result * 8) < value ? 1 : 0);
}
}
}
// File: @openzeppelin/contracts/utils/Strings.sol
// OpenZeppelin Contracts (last updated v4.8.0) (utils/Strings.sol)
pragma solidity ^0.8.0;
/**
* @dev String operations.
*/
library Strings {
bytes16 private constant _SYMBOLS = "0123456789abcdef";
uint8 private constant _ADDRESS_LENGTH = 20;
/**
* @dev Converts a `uint256` to its ASCII `string` decimal representation.
*/
function toString(uint256 value) internal pure returns (string memory) {
unchecked {
uint256 length = Math.log10(value) + 1;
string memory buffer = new string(length);
uint256 ptr;
/// @solidity memory-safe-assembly
assembly {
ptr := add(buffer, add(32, length))
}
while (true) {
ptr--;
/// @solidity memory-safe-assembly
assembly {
mstore8(ptr, byte(mod(value, 10), _SYMBOLS))
}
value /= 10;
if (value == 0) break;
}
return buffer;
}
}
/**
* @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
*/
function toHexString(uint256 value) internal pure returns (string memory) {
unchecked {
return toHexString(value, Math.log256(value) + 1);
}
}
/**
* @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
*/
function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
bytes memory buffer = new bytes(2 * length + 2);
buffer[0] = "0";
buffer[1] = "x";
for (uint256 i = 2 * length + 1; i > 1; --i) {
buffer[i] = _SYMBOLS[value & 0xf];
value >>= 4;
}
require(value == 0, "Strings: hex length insufficient");
return string(buffer);
}
/**
* @dev Converts an `address` with fixed length of 20 bytes to its not checksummed ASCII `string` hexadecimal representation.
*/
function toHexString(address addr) internal pure returns (string memory) {
return toHexString(uint256(uint160(addr)), _ADDRESS_LENGTH);
}
}
// File: @openzeppelin/contracts/utils/cryptography/ECDSA.sol
// OpenZeppelin Contracts (last updated v4.8.0) (utils/cryptography/ECDSA.sol)
pragma solidity ^0.8.0;
/**
* @dev Elliptic Curve Digital Signature Algorithm (ECDSA) operations.
*
* These functions can be used to verify that a message was signed by the holder
* of the private keys of a given address.
*/
library ECDSA {
enum RecoverError {
NoError,
InvalidSignature,
InvalidSignatureLength,
InvalidSignatureS,
InvalidSignatureV // Deprecated in v4.8
}
function _throwError(RecoverError error) private pure {
if (error == RecoverError.NoError) {
return; // no error: do nothing
} else if (error == RecoverError.InvalidSignature) {
revert("ECDSA: invalid signature");
} else if (error == RecoverError.InvalidSignatureLength) {
revert("ECDSA: invalid signature length");
} else if (error == RecoverError.InvalidSignatureS) {
revert("ECDSA: invalid signature 's' value");
}
}
/**
* @dev Returns the address that signed a hashed message (`hash`) with
* `signature` or error string. This address can then be used for verification purposes.
*
* The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
* this function rejects them by requiring the `s` value to be in the lower
* half order, and the `v` value to be either 27 or 28.
*
* IMPORTANT: `hash` _must_ be the result of a hash operation for the
* verification to be secure: it is possible to craft signatures that
* recover to arbitrary addresses for non-hashed data. A safe way to ensure
* this is by receiving a hash of the original message (which may otherwise
* be too long), and then calling {toEthSignedMessageHash} on it.
*
* Documentation for signature generation:
* - with https://web3js.readthedocs.io/en/v1.3.4/web3-eth-accounts.html#sign[Web3.js]
* - with https://docs.ethers.io/v5/api/signer/#Signer-signMessage[ethers]
*
* _Available since v4.3._
*/
function tryRecover(bytes32 hash, bytes memory signature) internal pure returns (address, RecoverError) {
if (signature.length == 65) {
bytes32 r;
bytes32 s;
uint8 v;
// ecrecover takes the signature parameters, and the only way to get them
// currently is to use assembly.
/// @solidity memory-safe-assembly
assembly {
r := mload(add(signature, 0x20))
s := mload(add(signature, 0x40))
v := byte(0, mload(add(signature, 0x60)))
}
return tryRecover(hash, v, r, s);
} else {
return (address(0), RecoverError.InvalidSignatureLength);
}
}
/**
* @dev Returns the address that signed a hashed message (`hash`) with
* `signature`. This address can then be used for verification purposes.
*
* The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
* this function rejects them by requiring the `s` value to be in the lower
* half order, and the `v` value to be either 27 or 28.
*
* IMPORTANT: `hash` _must_ be the result of a hash operation for the
* verification to be secure: it is possible to craft signatures that
* recover to arbitrary addresses for non-hashed data. A safe way to ensure
* this is by receiving a hash of the original message (which may otherwise
* be too long), and then calling {toEthSignedMessageHash} on it.
*/
function recover(bytes32 hash, bytes memory signature) internal pure returns (address) {
(address recovered, RecoverError error) = tryRecover(hash, signature);
_throwError(error);
return recovered;
}
/**
* @dev Overload of {ECDSA-tryRecover} that receives the `r` and `vs` short-signature fields separately.
*
* See https://eips.ethereum.org/EIPS/eip-2098[EIP-2098 short signatures]
*
* _Available since v4.3._
*/
function tryRecover(
bytes32 hash,
bytes32 r,
bytes32 vs
) internal pure returns (address, RecoverError) {
bytes32 s = vs & bytes32(0x7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff);
uint8 v = uint8((uint256(vs) >> 255) + 27);
return tryRecover(hash, v, r, s);
}
/**
* @dev Overload of {ECDSA-recover} that receives the `r and `vs` short-signature fields separately.
*
* _Available since v4.2._
*/
function recover(
bytes32 hash,
bytes32 r,
bytes32 vs
) internal pure returns (address) {
(address recovered, RecoverError error) = tryRecover(hash, r, vs);
_throwError(error);
return recovered;
}
/**
* @dev Overload of {ECDSA-tryRecover} that receives the `v`,
* `r` and `s` signature fields separately.
*
* _Available since v4.3._
*/
function tryRecover(
bytes32 hash,
uint8 v,
bytes32 r,
bytes32 s
) internal pure returns (address, RecoverError) {
// EIP-2 still allows signature malleability for ecrecover(). Remove this possibility and make the signature
// unique. Appendix F in the Ethereum Yellow paper (https://ethereum.github.io/yellowpaper/paper.pdf), defines
// the valid range for s in (301): 0 < s < secp256k1n ÷ 2 + 1, and for v in (302): v ∈ {27, 28}. Most
// signatures from current libraries generate a unique signature with an s-value in the lower half order.
//
// If your library generates malleable signatures, such as s-values in the upper range, calculate a new s-value
// with 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141 - s1 and flip v from 27 to 28 or
// vice versa. If your library also generates signatures with 0/1 for v instead 27/28, add 27 to v to accept
// these malleable signatures as well.
if (uint256(s) > 0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0) {
return (address(0), RecoverError.InvalidSignatureS);
}
// If the signature is valid (and not malleable), return the signer address
address signer = ecrecover(hash, v, r, s);
if (signer == address(0)) {
return (address(0), RecoverError.InvalidSignature);
}
return (signer, RecoverError.NoError);
}
/**
* @dev Overload of {ECDSA-recover} that receives the `v`,
* `r` and `s` signature fields separately.
*/
function recover(
bytes32 hash,
uint8 v,
bytes32 r,
bytes32 s
) internal pure returns (address) {
(address recovered, RecoverError error) = tryRecover(hash, v, r, s);
_throwError(error);
return recovered;
}
/**
* @dev Returns an Ethereum Signed Message, created from a `hash`. This
* produces hash corresponding to the one signed with the
* https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`]
* JSON-RPC method as part of EIP-191.
*
* See {recover}.
*/
function toEthSignedMessageHash(bytes32 hash) internal pure returns (bytes32) {
// 32 is the length in bytes of hash,
// enforced by the type signature above
return keccak256(abi.encodePacked("\x19Ethereum Signed Message:\n32", hash));
}
/**
* @dev Returns an Ethereum Signed Message, created from `s`. This
* produces hash corresponding to the one signed with the
* https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`]
* JSON-RPC method as part of EIP-191.
*
* See {recover}.
*/
function toEthSignedMessageHash(bytes memory s) internal pure returns (bytes32) {
return keccak256(abi.encodePacked("\x19Ethereum Signed Message:\n", Strings.toString(s.length), s));
}
/**
* @dev Returns an Ethereum Signed Typed Data, created from a
* `domainSeparator` and a `structHash`. This produces hash corresponding
* to the one signed with the
* https://eips.ethereum.org/EIPS/eip-712[`eth_signTypedData`]
* JSON-RPC method as part of EIP-712.
*
* See {recover}.
*/
function toTypedDataHash(bytes32 domainSeparator, bytes32 structHash) internal pure returns (bytes32) {
return keccak256(abi.encodePacked("\x19\x01", domainSeparator, structHash));
}
}
// File: @openzeppelin/contracts/utils/cryptography/EIP712.sol
// OpenZeppelin Contracts (last updated v4.8.0) (utils/cryptography/EIP712.sol)
pragma solidity ^0.8.0;
/**
* @dev https://eips.ethereum.org/EIPS/eip-712[EIP 712] is a standard for hashing and signing of typed structured data.
*
* The encoding specified in the EIP is very generic, and such a generic implementation in Solidity is not feasible,
* thus this contract does not implement the encoding itself. Protocols need to implement the type-specific encoding
* they need in their contracts using a combination of `abi.encode` and `keccak256`.
*
* This contract implements the EIP 712 domain separator ({_domainSeparatorV4}) that is used as part of the encoding
* scheme, and the final step of the encoding to obtain the message digest that is then signed via ECDSA
* ({_hashTypedDataV4}).
*
* The implementation of the domain separator was designed to be as efficient as possible while still properly updating
* the chain id to protect against replay attacks on an eventual fork of the chain.
*
* NOTE: This contract implements the version of the encoding known as "v4", as implemented by the JSON RPC method
* https://docs.metamask.io/guide/signing-data.html[`eth_signTypedDataV4` in MetaMask].
*
* _Available since v3.4._
*/
abstract contract EIP712 {
/* solhint-disable var-name-mixedcase */
// Cache the domain separator as an immutable value, but also store the chain id that it corresponds to, in order to
// invalidate the cached domain separator if the chain id changes.
bytes32 private immutable _CACHED_DOMAIN_SEPARATOR;
uint256 private immutable _CACHED_CHAIN_ID;
address private immutable _CACHED_THIS;
bytes32 private immutable _HASHED_NAME;
bytes32 private immutable _HASHED_VERSION;
bytes32 private immutable _TYPE_HASH;
/* solhint-enable var-name-mixedcase */
/**
* @dev Initializes the domain separator and parameter caches.
*
* The meaning of `name` and `version` is specified in
* https://eips.ethereum.org/EIPS/eip-712#definition-of-domainseparator[EIP 712]:
*
* - `name`: the user readable name of the signing domain, i.e. the name of the DApp or the protocol.
* - `version`: the current major version of the signing domain.
*
* NOTE: These parameters cannot be changed except through a xref:learn::upgrading-smart-contracts.adoc[smart
* contract upgrade].
*/
constructor(string memory name, string memory version) {
bytes32 hashedName = keccak256(bytes(name));
bytes32 hashedVersion = keccak256(bytes(version));
bytes32 typeHash = keccak256(
"EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)"
);
_HASHED_NAME = hashedName;
_HASHED_VERSION = hashedVersion;
_CACHED_CHAIN_ID = block.chainid;
_CACHED_DOMAIN_SEPARATOR = _buildDomainSeparator(typeHash, hashedName, hashedVersion);
_CACHED_THIS = address(this);
_TYPE_HASH = typeHash;
}
/**
* @dev Returns the domain separator for the current chain.
*/
function _domainSeparatorV4() internal view returns (bytes32) {
if (address(this) == _CACHED_THIS && block.chainid == _CACHED_CHAIN_ID) {
return _CACHED_DOMAIN_SEPARATOR;
} else {
return _buildDomainSeparator(_TYPE_HASH, _HASHED_NAME, _HASHED_VERSION);
}
}
function _buildDomainSeparator(
bytes32 typeHash,
bytes32 nameHash,
bytes32 versionHash
) private view returns (bytes32) {
return keccak256(abi.encode(typeHash, nameHash, versionHash, block.chainid, address(this)));
}
/**
* @dev Given an already https://eips.ethereum.org/EIPS/eip-712#definition-of-hashstruct[hashed struct], this
* function returns the hash of the fully encoded EIP712 message for this domain.
*
* This hash can be used together with {ECDSA-recover} to obtain the signer of a message. For example:
*
* ```solidity
* bytes32 digest = _hashTypedDataV4(keccak256(abi.encode(
* keccak256("Mail(address to,string contents)"),
* mailTo,
* keccak256(bytes(mailContents))
* )));
* address signer = ECDSA.recover(digest, signature);
* ```
*/
function _hashTypedDataV4(bytes32 structHash) internal view virtual returns (bytes32) {
return ECDSA.toTypedDataHash(_domainSeparatorV4(), structHash);
}
}
// File: @openzeppelin/contracts/utils/Address.sol
// OpenZeppelin Contracts (last updated v4.8.0) (utils/Address.sol)
pragma solidity ^0.8.1;
/**
* @dev Collection of functions related to the address type
*/
library Address {
/**
* @dev Returns true if `account` is a contract.
*
* [IMPORTANT]
* ====
* It is unsafe to assume that an address for which this function returns
* false is an externally-owned account (EOA) and not a contract.
*
* Among others, `isContract` will return false for the following
* types of addresses:
*
* - an externally-owned account
* - a contract in construction
* - an address where a contract will be created
* - an address where a contract lived, but was destroyed
* ====
*
* [IMPORTANT]
* ====
* You shouldn't rely on `isContract` to protect against flash loan attacks!
*
* Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
* like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
* constructor.
* ====
*/
function isContract(address account) internal view returns (bool) {
// This method relies on extcodesize/address.code.length, which returns 0
// for contracts in construction, since the code is only stored at the end
// of the constructor execution.
return account.code.length > 0;
}
/**
* @dev Replacement for Solidity's `transfer`: sends `amount` wei to
* `recipient`, forwarding all available gas and reverting on errors.
*
* https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
* of certain opcodes, possibly making contracts go over the 2300 gas limit
* imposed by `transfer`, making them unable to receive funds via
* `transfer`. {sendValue} removes this limitation.
*
* https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
*
* IMPORTANT: because control is transferred to `recipient`, care must be
* taken to not create reentrancy vulnerabilities. Consider using
* {ReentrancyGuard} or the
* https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
*/
function sendValue(address payable recipient, uint256 amount) internal {
require(address(this).balance >= amount, "Address: insufficient balance");
(bool success, ) = recipient.call{value: amount}("");
require(success, "Address: unable to send value, recipient may have reverted");
}
/**
* @dev Performs a Solidity function call using a low level `call`. A
* plain `call` is an unsafe replacement for a function call: use this
* function instead.
*
* If `target` reverts with a revert reason, it is bubbled up by this
* function (like regular Solidity function calls).
*
* Returns the raw returned data. To convert to the expected return value,
* use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
*
* Requirements:
*
* - `target` must be a contract.
* - calling `target` with `data` must not revert.
*
* _Available since v3.1._
*/
function functionCall(address target, bytes memory data) internal returns (bytes memory) {
return functionCallWithValue(target, data, 0, "Address: low-level call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
* `errorMessage` as a fallback revert reason when `target` reverts.
*
* _Available since v3.1._
*/
function functionCall(
address target,
bytes memory data,
string memory errorMessage
) internal returns (bytes memory) {
return functionCallWithValue(target, data, 0, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but also transferring `value` wei to `target`.
*
* Requirements:
*
* - the calling contract must have an ETH balance of at least `value`.
* - the called Solidity function must be `payable`.
*
* _Available since v3.1._
*/
function functionCallWithValue(
address target,
bytes memory data,
uint256 value
) internal returns (bytes memory) {
return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
}
/**
* @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
* with `errorMessage` as a fallback revert reason when `target` reverts.
*
* _Available since v3.1._
*/
function functionCallWithValue(
address target,
bytes memory data,
uint256 value,
string memory errorMessage
) internal returns (bytes memory) {
require(address(this).balance >= value, "Address: insufficient balance for call");
(bool success, bytes memory returndata) = target.call{value: value}(data);
return verifyCallResultFromTarget(target, success, returndata, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a static call.
*
* _Available since v3.3._
*/
function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
return functionStaticCall(target, data, "Address: low-level static call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
* but performing a static call.
*
* _Available since v3.3._
*/
function functionStaticCall(
address target,
bytes memory data,
string memory errorMessage
) internal view returns (bytes memory) {
(bool success, bytes memory returndata) = target.staticcall(data);
return verifyCallResultFromTarget(target, success, returndata, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a delegate call.
*
* _Available since v3.4._
*/
function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
return functionDelegateCall(target, data, "Address: low-level delegate call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
* but performing a delegate call.
*
* _Available since v3.4._
*/
function functionDelegateCall(
address target,
bytes memory data,
string memory errorMessage
) internal returns (bytes memory) {
(bool success, bytes memory returndata) = target.delegatecall(data);
return verifyCallResultFromTarget(target, success, returndata, errorMessage);
}
/**
* @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling
* the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract.
*
* _Available since v4.8._
*/
function verifyCallResultFromTarget(
address target,
bool success,
bytes memory returndata,
string memory errorMessage
) internal view returns (bytes memory) {
if (success) {
if (returndata.length == 0) {
// only check isContract if the call was successful and the return data is empty
// otherwise we already know that it was a contract
require(isContract(target), "Address: call to non-contract");
}
return returndata;
} else {
_revert(returndata, errorMessage);
}
}
/**
* @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the
* revert reason or using the provided one.
*
* _Available since v4.3._
*/
function verifyCallResult(
bool success,
bytes memory returndata,
string memory errorMessage
) internal pure returns (bytes memory) {
if (success) {
return returndata;
} else {
_revert(returndata, errorMessage);
}
}
function _revert(bytes memory returndata, string memory errorMessage) private pure {
// Look for revert reason and bubble it up if present
if (returndata.length > 0) {
// The easiest way to bubble the revert reason is using memory via assembly
/// @solidity memory-safe-assembly
assembly {
let returndata_size := mload(returndata)
revert(add(32, returndata), returndata_size)
}
} else {
revert(errorMessage);
}
}
}
// File: @openzeppelin/contracts/token/ERC20/extensions/draft-IERC20Permit.sol
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/draft-IERC20Permit.sol)
pragma solidity ^0.8.0;
/**
* @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
* https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
*
* Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
* presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn't
* need to send a transaction, and thus is not required to hold Ether at all.
*/
interface IERC20Permit {
/**
* @dev Sets `value` as the allowance of `spender` over ``owner``'s tokens,
* given ``owner``'s signed approval.
*
* IMPORTANT: The same issues {IERC20-approve} has related to transaction
* ordering also apply here.
*
* Emits an {Approval} event.
*
* Requirements:
*
* - `spender` cannot be the zero address.
* - `deadline` must be a timestamp in the future.
* - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`
* over the EIP712-formatted function arguments.
* - the signature must use ``owner``'s current nonce (see {nonces}).
*
* For more information on the signature format, see the
* https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP
* section].
*/
function permit(
address owner,
address spender,
uint256 value,
uint256 deadline,
uint8 v,
bytes32 r,
bytes32 s
) external;
/**
* @dev Returns the current nonce for `owner`. This value must be
* included whenever a signature is generated for {permit}.
*
* Every successful call to {permit} increases ``owner``'s nonce by one. This
* prevents a signature from being used multiple times.
*/
function nonces(address owner) external view returns (uint256);
/**
* @dev Returns the domain separator used in the encoding of the signature for {permit}, as defined by {EIP712}.
*/
// solhint-disable-next-line func-name-mixedcase
function DOMAIN_SEPARATOR() external view returns (bytes32);
}
// File: @openzeppelin/contracts/utils/Context.sol
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)
pragma solidity ^0.8.0;
/**
* @dev Provides information about the current execution context, including the
* sender of the transaction and its data. While these are generally available
* via msg.sender and msg.data, they should not be accessed in such a direct
* manner, since when dealing with meta-transactions the account sending and
* paying for execution may not be the actual sender (as far as an application
* is concerned).
*
* This contract is only required for intermediate, library-like contracts.
*/
abstract contract Context {
function _msgSender() internal view virtual returns (address) {
return msg.sender;
}
function _msgData() internal view virtual returns (bytes calldata) {
return msg.data;
}
}
// File: @openzeppelin/contracts/token/ERC20/IERC20.sol
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol)
pragma solidity ^0.8.0;
/**
* @dev Interface of the ERC20 standard as defined in the EIP.
*/
interface IERC20 {
/**
* @dev Emitted when `value` tokens are moved from one account (`from`) to
* another (`to`).
*
* Note that `value` may be zero.
*/
event Transfer(address indexed from, address indexed to, uint256 value);
/**
* @dev Emitted when the allowance of a `spender` for an `owner` is set by
* a call to {approve}. `value` is the new allowance.
*/
event Approval(address indexed owner, address indexed spender, uint256 value);
/**
* @dev Returns the amount of tokens in existence.
*/
function totalSupply() external view returns (uint256);
/**
* @dev Returns the amount of tokens owned by `account`.
*/
function balanceOf(address account) external view returns (uint256);
/**
* @dev Moves `amount` tokens from the caller's account to `to`.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transfer(address to, uint256 amount) external returns (bool);
/**
* @dev Returns the remaining number of tokens that `spender` will be
* allowed to spend on behalf of `owner` through {transferFrom}. This is
* zero by default.
*
* This value changes when {approve} or {transferFrom} are called.
*/
function allowance(address owner, address spender) external view returns (uint256);
/**
* @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* IMPORTANT: Beware that changing an allowance with this method brings the risk
* that someone may use both the old and the new allowance by unfortunate
* transaction ordering. One possible solution to mitigate this race
* condition is to first reduce the spender's allowance to 0 and set the
* desired value afterwards:
* https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
*
* Emits an {Approval} event.
*/
function approve(address spender, uint256 amount) external returns (bool);
/**
* @dev Moves `amount` tokens from `from` to `to` using the
* allowance mechanism. `amount` is then deducted from the caller's
* allowance.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transferFrom(
address from,
address to,
uint256 amount
) external returns (bool);
}
// File: @openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol
// OpenZeppelin Contracts (last updated v4.8.0) (token/ERC20/utils/SafeERC20.sol)
pragma solidity ^0.8.0;
/**
* @title SafeERC20
* @dev Wrappers around ERC20 operations that throw on failure (when the token
* contract returns false). Tokens that return no value (and instead revert or
* throw on failure) are also supported, non-reverting calls are assumed to be
* successful.
* To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
* which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
*/
library SafeERC20 {
using Address for address;
function safeTransfer(
IERC20 token,
address to,
uint256 value
) internal {
_callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
}
function safeTransferFrom(
IERC20 token,
address from,
address to,
uint256 value
) internal {
_callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
}
/**
* @dev Deprecated. This function has issues similar to the ones found in
* {IERC20-approve}, and its usage is discouraged.
*
* Whenever possible, use {safeIncreaseAllowance} and
* {safeDecreaseAllowance} instead.
*/
function safeApprove(
IERC20 token,
address spender,
uint256 value
) internal {
// safeApprove should only be called when setting an initial allowance,
// or when resetting it to zero. To increase and decrease it, use
// 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
require(
(value == 0) || (token.allowance(address(this), spender) == 0),
"SafeERC20: approve from non-zero to non-zero allowance"
);
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
}
function safeIncreaseAllowance(
IERC20 token,
address spender,
uint256 value
) internal {
uint256 newAllowance = token.allowance(address(this), spender) + value;
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
}
function safeDecreaseAllowance(
IERC20 token,
address spender,
uint256 value
) internal {
unchecked {
uint256 oldAllowance = token.allowance(address(this), spender);
require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
uint256 newAllowance = oldAllowance - value;
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
}
}
function safePermit(
IERC20Permit token,
address owner,
address spender,
uint256 value,
uint256 deadline,
uint8 v,
bytes32 r,
bytes32 s
) internal {
uint256 nonceBefore = token.nonces(owner);
token.permit(owner, spender, value, deadline, v, r, s);
uint256 nonceAfter = token.nonces(owner);
require(nonceAfter == nonceBefore + 1, "SafeERC20: permit did not succeed");
}
/**
* @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
* on the return value: the return value is optional (but if data is returned, it must not be false).
* @param token The token targeted by the call.
* @param data The call data (encoded using abi.encode or one of its variants).
*/
function _callOptionalReturn(IERC20 token, bytes memory data) private {
// We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
// we're implementing it ourselves. We use {Address-functionCall} to perform this call, which verifies that
// the target address contains contract code and also asserts for success in the low-level call.
bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
if (returndata.length > 0) {
// Return data is optional
require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
}
}
}
// File: @openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)
pragma solidity ^0.8.0;
/**
* @dev Interface for the optional metadata functions from the ERC20 standard.
*
* _Available since v4.1._
*/
interface IERC20Metadata is IERC20 {
/**
* @dev Returns the name of the token.
*/
function name() external view returns (string memory);
/**
* @dev Returns the symbol of the token.
*/
function symbol() external view returns (string memory);
/**
* @dev Returns the decimals places of the token.
*/
function decimals() external view returns (uint8);
}
// File: @openzeppelin/contracts/interfaces/IERC4626.sol
// OpenZeppelin Contracts (last updated v4.8.0) (interfaces/IERC4626.sol)
pragma solidity ^0.8.0;
/**
* @dev Interface of the ERC4626 "Tokenized Vault Standard", as defined in
* https://eips.ethereum.org/EIPS/eip-4626[ERC-4626].
*
* _Available since v4.7._
*/
interface IERC4626 is IERC20, IERC20Metadata {
event Deposit(address indexed sender, address indexed owner, uint256 assets, uint256 shares);
event Withdraw(
address indexed sender,
address indexed receiver,
address indexed owner,
uint256 assets,
uint256 shares
);
/**
* @dev Returns the address of the underlying token used for the Vault for accounting, depositing, and withdrawing.
*
* - MUST be an ERC-20 token contract.
* - MUST NOT revert.
*/
function asset() external view returns (address assetTokenAddress);
/**
* @dev Returns the total amount of the underlying asset that is “managed” by Vault.
*
* - SHOULD include any compounding that occurs from yield.
* - MUST be inclusive of any fees that are charged against assets in the Vault.
* - MUST NOT revert.
*/
function totalAssets() external view returns (uint256 totalManagedAssets);
/**
* @dev Returns the amount of shares that the Vault would exchange for the amount of assets provided, in an ideal
* scenario where all the conditions are met.
*
* - MUST NOT be inclusive of any fees that are charged against assets in the Vault.
* - MUST NOT show any variations depending on the caller.
* - MUST NOT reflect slippage or other on-chain conditions, when performing the actual exchange.
* - MUST NOT revert.
*
* NOTE: This calculation MAY NOT reflect the “per-user” price-per-share, and instead should reflect the
* “average-user’s” price-per-share, meaning what the average user should expect to see when exchanging to and
* from.
*/
function convertToShares(uint256 assets) external view returns (uint256 shares);
/**
* @dev Returns the amount of assets that the Vault would exchange for the amount of shares provided, in an ideal
* scenario where all the conditions are met.
*
* - MUST NOT be inclusive of any fees that are charged against assets in the Vault.
* - MUST NOT show any variations depending on the caller.
* - MUST NOT reflect slippage or other on-chain conditions, when performing the actual exchange.
* - MUST NOT revert.
*
* NOTE: This calculation MAY NOT reflect the “per-user” price-per-share, and instead should reflect the
* “average-user’s” price-per-share, meaning what the average user should expect to see when exchanging to and
* from.
*/
function convertToAssets(uint256 shares) external view returns (uint256 assets);
/**
* @dev Returns the maximum amount of the underlying asset that can be deposited into the Vault for the receiver,
* through a deposit call.
*
* - MUST return a limited value if receiver is subject to some deposit limit.
* - MUST return 2 ** 256 - 1 if there is no limit on the maximum amount of assets that may be deposited.
* - MUST NOT revert.
*/
function maxDeposit(address receiver) external view returns (uint256 maxAssets);
/**
* @dev Allows an on-chain or off-chain user to simulate the effects of their deposit at the current block, given
* current on-chain conditions.
*
* - MUST return as close to and no more than the exact amount of Vault shares that would be minted in a deposit
* call in the same transaction. I.e. deposit should return the same or more shares as previewDeposit if called
* in the same transaction.
* - MUST NOT account for deposit limits like those returned from maxDeposit and should always act as though the
* deposit would be accepted, regardless if the user has enough tokens approved, etc.
* - MUST be inclusive of deposit fees. Integrators should be aware of the existence of deposit fees.
* - MUST NOT revert.
*
* NOTE: any unfavorable discrepancy between convertToShares and previewDeposit SHOULD be considered slippage in
* share price or some other type of condition, meaning the depositor will lose assets by depositing.
*/
function previewDeposit(uint256 assets) external view returns (uint256 shares);
/**
* @dev Mints shares Vault shares to receiver by depositing exactly amount of underlying tokens.
*
* - MUST emit the Deposit event.
* - MAY support an additional flow in which the underlying tokens are owned by the Vault contract before the
* deposit execution, and are accounted for during deposit.
* - MUST revert if all of assets cannot be deposited (due to deposit limit being reached, slippage, the user not
* approving enough underlying tokens to the Vault contract, etc).
*
* NOTE: most implementations will require pre-approval of the Vault with the Vault’s underlying asset token.
*/
function deposit(uint256 assets, address receiver) external returns (uint256 shares);
/**
* @dev Returns the maximum amount of the Vault shares that can be minted for the receiver, through a mint call.
* - MUST return a limited value if receiver is subject to some mint limit.
* - MUST return 2 ** 256 - 1 if there is no limit on the maximum amount of shares that may be minted.
* - MUST NOT revert.
*/
function maxMint(address receiver) external view returns (uint256 maxShares);
/**
* @dev Allows an on-chain or off-chain user to simulate the effects of their mint at the current block, given
* current on-chain conditions.
*
* - MUST return as close to and no fewer than the exact amount of assets that would be deposited in a mint call
* in the same transaction. I.e. mint should return the same or fewer assets as previewMint if called in the
* same transaction.
* - MUST NOT account for mint limits like those returned from maxMint and should always act as though the mint
* would be accepted, regardless if the user has enough tokens approved, etc.
* - MUST be inclusive of deposit fees. Integrators should be aware of the existence of deposit fees.
* - MUST NOT revert.
*
* NOTE: any unfavorable discrepancy between convertToAssets and previewMint SHOULD be considered slippage in
* share price or some other type of condition, meaning the depositor will lose assets by minting.
*/
function previewMint(uint256 shares) external view returns (uint256 assets);
/**
* @dev Mints exactly shares Vault shares to receiver by depositing amount of underlying tokens.
*
* - MUST emit the Deposit event.
* - MAY support an additional flow in which the underlying tokens are owned by the Vault contract before the mint
* execution, and are accounted for during mint.
* - MUST revert if all of shares cannot be minted (due to deposit limit being reached, slippage, the user not
* approving enough underlying tokens to the Vault contract, etc).
*
* NOTE: most implementations will require pre-approval of the Vault with the Vault’s underlying asset token.
*/
function mint(uint256 shares, address receiver) external returns (uint256 assets);
/**
* @dev Returns the maximum amount of the underlying asset that can be withdrawn from the owner balance in the
* Vault, through a withdraw call.
*
* - MUST return a limited value if owner is subject to some withdrawal limit or timelock.
* - MUST NOT revert.
*/
function maxWithdraw(address owner) external view returns (uint256 maxAssets);
/**
* @dev Allows an on-chain or off-chain user to simulate the effects of their withdrawal at the current block,
* given current on-chain conditions.
*
* - MUST return as close to and no fewer than the exact amount of Vault shares that would be burned in a withdraw
* call in the same transaction. I.e. withdraw should return the same or fewer shares as previewWithdraw if
* called
* in the same transaction.
* - MUST NOT account for withdrawal limits like those returned from maxWithdraw and should always act as though
* the withdrawal would be accepted, regardless if the user has enough shares, etc.
* - MUST be inclusive of withdrawal fees. Integrators should be aware of the existence of withdrawal fees.
* - MUST NOT revert.
*
* NOTE: any unfavorable discrepancy between convertToShares and previewWithdraw SHOULD be considered slippage in
* share price or some other type of condition, meaning the depositor will lose assets by depositing.
*/
function previewWithdraw(uint256 assets) external view returns (uint256 shares);
/**
* @dev Burns shares from owner and sends exactly assets of underlying tokens to receiver.
*
* - MUST emit the Withdraw event.
* - MAY support an additional flow in which the underlying tokens are owned by the Vault contract before the
* withdraw execution, and are accounted for during withdraw.
* - MUST revert if all of assets cannot be withdrawn (due to withdrawal limit being reached, slippage, the owner
* not having enough shares, etc).
*
* Note that some implementations will require pre-requesting to the Vault before a withdrawal may be performed.
* Those methods should be performed separately.
*/
function withdraw(
uint256 assets,
address receiver,
address owner
) external returns (uint256 shares);
/**
* @dev Returns the maximum amount of Vault shares that can be redeemed from the owner balance in the Vault,
* through a redeem call.
*
* - MUST return a limited value if owner is subject to some withdrawal limit or timelock.
* - MUST return balanceOf(owner) if owner is not subject to any withdrawal limit or timelock.
* - MUST NOT revert.
*/
function maxRedeem(address owner) external view returns (uint256 maxShares);
/**
* @dev Allows an on-chain or off-chain user to simulate the effects of their redeemption at the current block,
* given current on-chain conditions.
*
* - MUST return as close to and no more than the exact amount of assets that would be withdrawn in a redeem call
* in the same transaction. I.e. redeem should return the same or more assets as previewRedeem if called in the
* same transaction.
* - MUST NOT account for redemption limits like those returned from maxRedeem and should always act as though the
* redemption would be accepted, regardless if the user has enough shares, etc.
* - MUST be inclusive of withdrawal fees. Integrators should be aware of the existence of withdrawal fees.
* - MUST NOT revert.
*
* NOTE: any unfavorable discrepancy between convertToAssets and previewRedeem SHOULD be considered slippage in
* share price or some other type of condition, meaning the depositor will lose assets by redeeming.
*/
function previewRedeem(uint256 shares) external view returns (uint256 assets);
/**
* @dev Burns exactly shares from owner and sends assets of underlying tokens to receiver.
*
* - MUST emit the Withdraw event.
* - MAY support an additional flow in which the underlying tokens are owned by the Vault contract before the
* redeem execution, and are accounted for during redeem.
* - MUST revert if all of shares cannot be redeemed (due to withdrawal limit being reached, slippage, the owner
* not having enough shares, etc).
*
* NOTE: some implementations will require pre-requesting to the Vault before a withdrawal may be performed.
* Those methods should be performed separately.
*/
function redeem(
uint256 shares,
address receiver,
address owner
) external returns (uint256 assets);
}
// File: @openzeppelin/contracts/token/ERC20/ERC20.sol
// OpenZeppelin Contracts (last updated v4.8.0) (token/ERC20/ERC20.sol)
pragma solidity ^0.8.0;
/**
* @dev Implementation of the {IERC20} interface.
*
* This implementation is agnostic to the way tokens are created. This means
* that a supply mechanism has to be added in a derived contract using {_mint}.
* For a generic mechanism see {ERC20PresetMinterPauser}.
*
* TIP: For a detailed writeup see our guide
* https://forum.openzeppelin.com/t/how-to-implement-erc20-supply-mechanisms/226[How
* to implement supply mechanisms].
*
* We have followed general OpenZeppelin Contracts guidelines: functions revert
* instead returning `false` on failure. This behavior is nonetheless
* conventional and does not conflict with the expectations of ERC20
* applications.
*
* Additionally, an {Approval} event is emitted on calls to {transferFrom}.
* This allows applications to reconstruct the allowance for all accounts just
* by listening to said events. Other implementations of the EIP may not emit
* these events, as it isn't required by the specification.
*
* Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
* functions have been added to mitigate the well-known issues around setting
* allowances. See {IERC20-approve}.
*/
contract ERC20 is Context, IERC20, IERC20Metadata {
mapping(address => uint256) private _balances;
mapping(address => mapping(address => uint256)) private _allowances;
uint256 private _totalSupply;
string private _name;
string private _symbol;
/**
* @dev Sets the values for {name} and {symbol}.
*
* The default value of {decimals} is 18. To select a different value for
* {decimals} you should overload it.
*
* All two of these values are immutable: they can only be set once during
* construction.
*/
constructor(string memory name_, string memory symbol_) {
_name = name_;
_symbol = symbol_;
}
/**
* @dev Returns the name of the token.
*/
function name() public view virtual override returns (string memory) {
return _name;
}
/**
* @dev Returns the symbol of the token, usually a shorter version of the
* name.
*/
function symbol() public view virtual override returns (string memory) {
return _symbol;
}
/**
* @dev Returns the number of decimals used to get its user representation.
* For example, if `decimals` equals `2`, a balance of `505` tokens should
* be displayed to a user as `5.05` (`505 / 10 ** 2`).
*
* Tokens usually opt for a value of 18, imitating the relationship between
* Ether and Wei. This is the value {ERC20} uses, unless this function is
* overridden;
*
* NOTE: This information is only used for _display_ purposes: it in
* no way affects any of the arithmetic of the contract, including
* {IERC20-balanceOf} and {IERC20-transfer}.
*/
function decimals() public view virtual override returns (uint8) {
return 18;
}
/**
* @dev See {IERC20-totalSupply}.
*/
function totalSupply() public view virtual override returns (uint256) {
return _totalSupply;
}
/**
* @dev See {IERC20-balanceOf}.
*/
function balanceOf(address account) public view virtual override returns (uint256) {
return _balances[account];
}
/**
* @dev See {IERC20-transfer}.
*
* Requirements:
*
* - `to` cannot be the zero address.
* - the caller must have a balance of at least `amount`.
*/
function transfer(address to, uint256 amount) public virtual override returns (bool) {
address owner = _msgSender();
_transfer(owner, to, amount);
return true;
}
/**
* @dev See {IERC20-allowance}.
*/
function allowance(address owner, address spender) public view virtual override returns (uint256) {
return _allowances[owner][spender];
}
/**
* @dev See {IERC20-approve}.
*
* NOTE: If `amount` is the maximum `uint256`, the allowance is not updated on
* `transferFrom`. This is semantically equivalent to an infinite approval.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/
function approve(address spender, uint256 amount) public virtual override returns (bool) {
address owner = _msgSender();
_approve(owner, spender, amount);
return true;
}
/**
* @dev See {IERC20-transferFrom}.
*
* Emits an {Approval} event indicating the updated allowance. This is not
* required by the EIP. See the note at the beginning of {ERC20}.
*
* NOTE: Does not update the allowance if the current allowance
* is the maximum `uint256`.
*
* Requirements:
*
* - `from` and `to` cannot be the zero address.
* - `from` must have a balance of at least `amount`.
* - the caller must have allowance for ``from``'s tokens of at least
* `amount`.
*/
function transferFrom(
address from,
address to,
uint256 amount
) public virtual override returns (bool) {
address spender = _msgSender();
_spendAllowance(from, spender, amount);
_transfer(from, to, amount);
return true;
}
/**
* @dev Atomically increases the allowance granted to `spender` by the caller.
*
* This is an alternative to {approve} that can be used as a mitigation for
* problems described in {IERC20-approve}.
*
* Emits an {Approval} event indicating the updated allowance.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/
function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
address owner = _msgSender();
_approve(owner, spender, allowance(owner, spender) + addedValue);
return true;
}
/**
* @dev Atomically decreases the allowance granted to `spender` by the caller.
*
* This is an alternative to {approve} that can be used as a mitigation for
* problems described in {IERC20-approve}.
*
* Emits an {Approval} event indicating the updated allowance.
*
* Requirements:
*
* - `spender` cannot be the zero address.
* - `spender` must have allowance for the caller of at least
* `subtractedValue`.
*/
function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
address owner = _msgSender();
uint256 currentAllowance = allowance(owner, spender);
require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
unchecked {
_approve(owner, spender, currentAllowance - subtractedValue);
}
return true;
}
/**
* @dev Moves `amount` of tokens from `from` to `to`.
*
* This internal function is equivalent to {transfer}, and can be used to
* e.g. implement automatic token fees, slashing mechanisms, etc.
*
* Emits a {Transfer} event.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `from` must have a balance of at least `amount`.
*/
function _transfer(
address from,
address to,
uint256 amount
) internal virtual {
require(from != address(0), "ERC20: transfer from the zero address");
require(to != address(0), "ERC20: transfer to the zero address");
_beforeTokenTransfer(from, to, amount);
uint256 fromBalance = _balances[from];
require(fromBalance >= amount, "ERC20: transfer amount exceeds balance");
unchecked {
_balances[from] = fromBalance - amount;
// Overflow not possible: the sum of all balances is capped by totalSupply, and the sum is preserved by
// decrementing then incrementing.
_balances[to] += amount;
}
emit Transfer(from, to, amount);
_afterTokenTransfer(from, to, amount);
}
/** @dev Creates `amount` tokens and assigns them to `account`, increasing
* the total supply.
*
* Emits a {Transfer} event with `from` set to the zero address.
*
* Requirements:
*
* - `account` cannot be the zero address.
*/
function _mint(address account, uint256 amount) internal virtual {
require(account != address(0), "ERC20: mint to the zero address");
_beforeTokenTransfer(address(0), account, amount);
_totalSupply += amount;
unchecked {
// Overflow not possible: balance + amount is at most totalSupply + amount, which is checked above.
_balances[account] += amount;
}
emit Transfer(address(0), account, amount);
_afterTokenTransfer(address(0), account, amount);
}
/**
* @dev Destroys `amount` tokens from `account`, reducing the
* total supply.
*
* Emits a {Transfer} event with `to` set to the zero address.
*
* Requirements:
*
* - `account` cannot be the zero address.
* - `account` must have at least `amount` tokens.
*/
function _burn(address account, uint256 amount) internal virtual {
require(account != address(0), "ERC20: burn from the zero address");
_beforeTokenTransfer(account, address(0), amount);
uint256 accountBalance = _balances[account];
require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
unchecked {
_balances[account] = accountBalance - amount;
// Overflow not possible: amount <= accountBalance <= totalSupply.
_totalSupply -= amount;
}
emit Transfer(account, address(0), amount);
_afterTokenTransfer(account, address(0), amount);
}
/**
* @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
*
* This internal function is equivalent to `approve`, and can be used to
* e.g. set automatic allowances for certain subsystems, etc.
*
* Emits an {Approval} event.
*
* Requirements:
*
* - `owner` cannot be the zero address.
* - `spender` cannot be the zero address.
*/
function _approve(
address owner,
address spender,
uint256 amount
) internal virtual {
require(owner != address(0), "ERC20: approve from the zero address");
require(spender != address(0), "ERC20: approve to the zero address");
_allowances[owner][spender] = amount;
emit Approval(owner, spender, amount);
}
/**
* @dev Updates `owner` s allowance for `spender` based on spent `amount`.
*
* Does not update the allowance amount in case of infinite allowance.
* Revert if not enough allowance is available.
*
* Might emit an {Approval} event.
*/
function _spendAllowance(
address owner,
address spender,
uint256 amount
) internal virtual {
uint256 currentAllowance = allowance(owner, spender);
if (currentAllowance != type(uint256).max) {
require(currentAllowance >= amount, "ERC20: insufficient allowance");
unchecked {
_approve(owner, spender, currentAllowance - amount);
}
}
}
/**
* @dev Hook that is called before any transfer of tokens. This includes
* minting and burning.
*
* Calling conditions:
*
* - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
* will be transferred to `to`.
* - when `from` is zero, `amount` tokens will be minted for `to`.
* - when `to` is zero, `amount` of ``from``'s tokens will be burned.
* - `from` and `to` are never both zero.
*
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
*/
function _beforeTokenTransfer(
address from,
address to,
uint256 amount
) internal virtual {}
/**
* @dev Hook that is called after any transfer of tokens. This includes
* minting and burning.
*
* Calling conditions:
*
* - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
* has been transferred to `to`.
* - when `from` is zero, `amount` tokens have been minted for `to`.
* - when `to` is zero, `amount` of ``from``'s tokens have been burned.
* - `from` and `to` are never both zero.
*
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
*/
function _afterTokenTransfer(
address from,
address to,
uint256 amount
) internal virtual {}
}
// File: @openzeppelin/contracts/token/ERC20/extensions/draft-ERC20Permit.sol
// OpenZeppelin Contracts (last updated v4.8.0) (token/ERC20/extensions/draft-ERC20Permit.sol)
pragma solidity ^0.8.0;
/**
* @dev Implementation of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
* https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
*
* Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
* presenting a message signed by the account. By not relying on `{IERC20-approve}`, the token holder account doesn't
* need to send a transaction, and thus is not required to hold Ether at all.
*
* _Available since v3.4._
*/
abstract contract ERC20Permit is ERC20, IERC20Permit, EIP712 {
using Counters for Counters.Counter;
mapping(address => Counters.Counter) private _nonces;
// solhint-disable-next-line var-name-mixedcase
bytes32 private constant _PERMIT_TYPEHASH =
keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)");
/**
* @dev In previous versions `_PERMIT_TYPEHASH` was declared as `immutable`.
* However, to ensure consistency with the upgradeable transpiler, we will continue
* to reserve a slot.
* @custom:oz-renamed-from _PERMIT_TYPEHASH
*/
// solhint-disable-next-line var-name-mixedcase
bytes32 private _PERMIT_TYPEHASH_DEPRECATED_SLOT;
/**
* @dev Initializes the {EIP712} domain separator using the `name` parameter, and setting `version` to `"1"`.
*
* It's a good idea to use the same `name` that is defined as the ERC20 token name.
*/
constructor(string memory name) EIP712(name, "1") {}
/**
* @dev See {IERC20Permit-permit}.
*/
function permit(
address owner,
address spender,
uint256 value,
uint256 deadline,
uint8 v,
bytes32 r,
bytes32 s
) public virtual override {
require(block.timestamp <= deadline, "ERC20Permit: expired deadline");
bytes32 structHash = keccak256(abi.encode(_PERMIT_TYPEHASH, owner, spender, value, _useNonce(owner), deadline));
bytes32 hash = _hashTypedDataV4(structHash);
address signer = ECDSA.recover(hash, v, r, s);
require(signer == owner, "ERC20Permit: invalid signature");
_approve(owner, spender, value);
}
/**
* @dev See {IERC20Permit-nonces}.
*/
function nonces(address owner) public view virtual override returns (uint256) {
return _nonces[owner].current();
}
/**
* @dev See {IERC20Permit-DOMAIN_SEPARATOR}.
*/
// solhint-disable-next-line func-name-mixedcase
function DOMAIN_SEPARATOR() external view override returns (bytes32) {
return _domainSeparatorV4();
}
/**
* @dev "Consume a nonce": return the current value and increment.
*
* _Available since v4.1._
*/
function _useNonce(address owner) internal virtual returns (uint256 current) {
Counters.Counter storage nonce = _nonces[owner];
current = nonce.current();
nonce.increment();
}
}
// File: @openzeppelin/contracts/token/ERC20/extensions/ERC4626.sol
// OpenZeppelin Contracts (last updated v4.8.1) (token/ERC20/extensions/ERC4626.sol)
pragma solidity ^0.8.0;
/**
* @dev Implementation of the ERC4626 "Tokenized Vault Standard" as defined in
* https://eips.ethereum.org/EIPS/eip-4626[EIP-4626].
*
* This extension allows the minting and burning of "shares" (represented using the ERC20 inheritance) in exchange for
* underlying "assets" through standardized {deposit}, {mint}, {redeem} and {burn} workflows. This contract extends
* the ERC20 standard. Any additional extensions included along it would affect the "shares" token represented by this
* contract and not the "assets" token which is an independent contract.
*
* CAUTION: When the vault is empty or nearly empty, deposits are at high risk of being stolen through frontrunning with
* a "donation" to the vault that inflates the price of a share. This is variously known as a donation or inflation
* attack and is essentially a problem of slippage. Vault deployers can protect against this attack by making an initial
* deposit of a non-trivial amount of the asset, such that price manipulation becomes infeasible. Withdrawals may
* similarly be affected by slippage. Users can protect against this attack as well unexpected slippage in general by
* verifying the amount received is as expected, using a wrapper that performs these checks such as
* https://github.com/fei-protocol/ERC4626#erc4626router-and-base[ERC4626Router].
*
* _Available since v4.7._
*/
abstract contract ERC4626 is ERC20, IERC4626 {
using Math for uint256;
IERC20 private immutable _asset;
uint8 private immutable _decimals;
/**
* @dev Set the underlying asset contract. This must be an ERC20-compatible contract (ERC20 or ERC777).
*/
constructor(IERC20 asset_) {
(bool success, uint8 assetDecimals) = _tryGetAssetDecimals(asset_);
_decimals = success ? assetDecimals : super.decimals();
_asset = asset_;
}
/**
* @dev Attempts to fetch the asset decimals. A return value of false indicates that the attempt failed in some way.
*/
function _tryGetAssetDecimals(IERC20 asset_) private view returns (bool, uint8) {
(bool success, bytes memory encodedDecimals) = address(asset_).staticcall(
abi.encodeWithSelector(IERC20Metadata.decimals.selector)
);
if (success && encodedDecimals.length >= 32) {
uint256 returnedDecimals = abi.decode(encodedDecimals, (uint256));
if (returnedDecimals <= type(uint8).max) {
return (true, uint8(returnedDecimals));
}
}
return (false, 0);
}
/**
* @dev Decimals are read from the underlying asset in the constructor and cached. If this fails (e.g., the asset
* has not been created yet), the cached value is set to a default obtained by `super.decimals()` (which depends on
* inheritance but is most likely 18). Override this function in order to set a guaranteed hardcoded value.
* See {IERC20Metadata-decimals}.
*/
function decimals() public view virtual override(IERC20Metadata, ERC20) returns (uint8) {
return _decimals;
}
/** @dev See {IERC4626-asset}. */
function asset() public view virtual override returns (address) {
return address(_asset);
}
/** @dev See {IERC4626-totalAssets}. */
function totalAssets() public view virtual override returns (uint256) {
return _asset.balanceOf(address(this));
}
/** @dev See {IERC4626-convertToShares}. */
function convertToShares(uint256 assets) public view virtual override returns (uint256 shares) {
return _convertToShares(assets, Math.Rounding.Down);
}
/** @dev See {IERC4626-convertToAssets}. */
function convertToAssets(uint256 shares) public view virtual override returns (uint256 assets) {
return _convertToAssets(shares, Math.Rounding.Down);
}
/** @dev See {IERC4626-maxDeposit}. */
function maxDeposit(address) public view virtual override returns (uint256) {
return _isVaultCollateralized() ? type(uint256).max : 0;
}
/** @dev See {IERC4626-maxMint}. */
function maxMint(address) public view virtual override returns (uint256) {
return type(uint256).max;
}
/** @dev See {IERC4626-maxWithdraw}. */
function maxWithdraw(address owner) public view virtual override returns (uint256) {
return _convertToAssets(balanceOf(owner), Math.Rounding.Down);
}
/** @dev See {IERC4626-maxRedeem}. */
function maxRedeem(address owner) public view virtual override returns (uint256) {
return balanceOf(owner);
}
/** @dev See {IERC4626-previewDeposit}. */
function previewDeposit(uint256 assets) public view virtual override returns (uint256) {
return _convertToShares(assets, Math.Rounding.Down);
}
/** @dev See {IERC4626-previewMint}. */
function previewMint(uint256 shares) public view virtual override returns (uint256) {
return _convertToAssets(shares, Math.Rounding.Up);
}
/** @dev See {IERC4626-previewWithdraw}. */
function previewWithdraw(uint256 assets) public view virtual override returns (uint256) {
return _convertToShares(assets, Math.Rounding.Up);
}
/** @dev See {IERC4626-previewRedeem}. */
function previewRedeem(uint256 shares) public view virtual override returns (uint256) {
return _convertToAssets(shares, Math.Rounding.Down);
}
/** @dev See {IERC4626-deposit}. */
function deposit(uint256 assets, address receiver) public virtual override returns (uint256) {
require(assets <= maxDeposit(receiver), "ERC4626: deposit more than max");
uint256 shares = previewDeposit(assets);
_deposit(_msgSender(), receiver, assets, shares);
return shares;
}
/** @dev See {IERC4626-mint}.
*
* As opposed to {deposit}, minting is allowed even if the vault is in a state where the price of a share is zero.
* In this case, the shares will be minted without requiring any assets to be deposited.
*/
function mint(uint256 shares, address receiver) public virtual override returns (uint256) {
require(shares <= maxMint(receiver), "ERC4626: mint more than max");
uint256 assets = previewMint(shares);
_deposit(_msgSender(), receiver, assets, shares);
return assets;
}
/** @dev See {IERC4626-withdraw}. */
function withdraw(
uint256 assets,
address receiver,
address owner
) public virtual override returns (uint256) {
require(assets <= maxWithdraw(owner), "ERC4626: withdraw more than max");
uint256 shares = previewWithdraw(assets);
_withdraw(_msgSender(), receiver, owner, assets, shares);
return shares;
}
/** @dev See {IERC4626-redeem}. */
function redeem(
uint256 shares,
address receiver,
address owner
) public virtual override returns (uint256) {
require(shares <= maxRedeem(owner), "ERC4626: redeem more than max");
uint256 assets = previewRedeem(shares);
_withdraw(_msgSender(), receiver, owner, assets, shares);
return assets;
}
/**
* @dev Internal conversion function (from assets to shares) with support for rounding direction.
*
* Will revert if assets > 0, totalSupply > 0 and totalAssets = 0. That corresponds to a case where any asset
* would represent an infinite amount of shares.
*/
function _convertToShares(uint256 assets, Math.Rounding rounding) internal view virtual returns (uint256 shares) {
uint256 supply = totalSupply();
return
(assets == 0 || supply == 0)
? _initialConvertToShares(assets, rounding)
: assets.mulDiv(supply, totalAssets(), rounding);
}
/**
* @dev Internal conversion function (from assets to shares) to apply when the vault is empty.
*
* NOTE: Make sure to keep this function consistent with {_initialConvertToAssets} when overriding it.
*/
function _initialConvertToShares(
uint256 assets,
Math.Rounding /*rounding*/
) internal view virtual returns (uint256 shares) {
return assets;
}
/**
* @dev Internal conversion function (from shares to assets) with support for rounding direction.
*/
function _convertToAssets(uint256 shares, Math.Rounding rounding) internal view virtual returns (uint256 assets) {
uint256 supply = totalSupply();
return
(supply == 0) ? _initialConvertToAssets(shares, rounding) : shares.mulDiv(totalAssets(), supply, rounding);
}
/**
* @dev Internal conversion function (from shares to assets) to apply when the vault is empty.
*
* NOTE: Make sure to keep this function consistent with {_initialConvertToShares} when overriding it.
*/
function _initialConvertToAssets(
uint256 shares,
Math.Rounding /*rounding*/
) internal view virtual returns (uint256 assets) {
return shares;
}
/**
* @dev Deposit/mint common workflow.
*/
function _deposit(
address caller,
address receiver,
uint256 assets,
uint256 shares
) internal virtual {
// If _asset is ERC777, `transferFrom` can trigger a reenterancy BEFORE the transfer happens through the
// `tokensToSend` hook. On the other hand, the `tokenReceived` hook, that is triggered after the transfer,
// calls the vault, which is assumed not malicious.
//
// Conclusion: we need to do the transfer before we mint so that any reentrancy would happen before the
// assets are transferred and before the shares are minted, which is a valid state.
// slither-disable-next-line reentrancy-no-eth
SafeERC20.safeTransferFrom(_asset, caller, address(this), assets);
_mint(receiver, shares);
emit Deposit(caller, receiver, assets, shares);
}
/**
* @dev Withdraw/redeem common workflow.
*/
function _withdraw(
address caller,
address receiver,
address owner,
uint256 assets,
uint256 shares
) internal virtual {
if (caller != owner) {
_spendAllowance(owner, caller, shares);
}
// If _asset is ERC777, `transfer` can trigger a reentrancy AFTER the transfer happens through the
// `tokensReceived` hook. On the other hand, the `tokensToSend` hook, that is triggered before the transfer,
// calls the vault, which is assumed not malicious.
//
// Conclusion: we need to do the transfer after the burn so that any reentrancy would happen after the
// shares are burned and after the assets are transferred, which is a valid state.
_burn(owner, shares);
SafeERC20.safeTransfer(_asset, receiver, assets);
emit Withdraw(caller, receiver, owner, assets, shares);
}
/**
* @dev Checks if vault is "healthy" in the sense of having assets backing the circulating shares.
*/
function _isVaultCollateralized() private view returns (bool) {
return totalAssets() > 0 || totalSupply() == 0;
}
}
// File: contracts/vXDEFI.sol
pragma solidity =0.8.18;
/**
* @title XDEFI Vault - for vXDEFI (vXDEFI)
* @author David P. ([email protected])
*/
contract XDEFIVault is ERC4626, ERC20Permit {
bytes32 private immutable _salt;
constructor(address underlying) ERC20("vXDEFI", "vXDEFI") ERC4626(IERC20(underlying)) ERC20Permit("vXDEFI") {
require(underlying != address(0), "Underlying token address cannot be 0x0");
_salt = keccak256(abi.encodePacked(block.timestamp, msg.sender));
}
function decimals() public view virtual override(ERC20, ERC4626) returns (uint8) {
return ERC4626.decimals();
}
/**
* @dev See {EIP-5267}.
*/
function eip712Domain() public view virtual returns (bytes1 fields, string memory name, string memory version, uint256 chainId, address verifyingContract, bytes32 salt, uint256[] memory extensions) {
return (
hex"0f", // 01111
"vXDEFI",
"1",
block.chainid,
address(this),
_salt,
new uint256[](0)
);
}
}